I am reading the book: Flask Web Developmen. Below are the book's codes for adding an icon in the address bar:
{% block head %}
{{ super() }}
<link rel="shortcut icon" href="{{ url_for('static', filename='favicon.ico') }}"
type="image/x-icon">
<link rel="icon" href="{{ url_for('static', filename='favicon.ico') }}"
type="image/x-icon">
{% endblock %}
My question is: why it needs two links to add one icon.
In HTML, this oneline <link rel="shortcut icon" href="static/favicon.ico">
is enough for this task. Doesn't it?